| /* |
| * Copyright 2021 Google LLC. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef AtlasInstancedHelper_DEFINED |
| #define AtlasInstancedHelper_DEFINED |
| |
| #include "src/core/SkIPoint16.h" |
| #include "src/gpu/ganesh/GrGeometryProcessor.h" |
| #include "src/gpu/ganesh/GrSurfaceProxyView.h" |
| #include "src/gpu/ganesh/glsl/GrGLSLUniformHandler.h" |
| |
| namespace skgpu::ganesh { |
| |
| // This class encapsulates all the necessary steps for an instanced GrGeometryProcessor to clip |
| // against a path mask from an atlas. |
| class AtlasInstancedHelper { |
| public: |
| enum class ShaderFlags { |
| kNone = 0, |
| kInvertCoverage = 1 << 0, |
| kCheckBounds = 1 << 1 |
| }; |
| |
| GR_DECL_BITFIELD_CLASS_OPS_FRIENDS(ShaderFlags); |
| |
| constexpr static int kNumShaderFlags = 2; |
| |
| AtlasInstancedHelper(GrSurfaceProxyView atlasView, ShaderFlags shaderFlags) |
| : fAtlasProxy(atlasView.detachProxy()) |
| , fAtlasSwizzle(atlasView.swizzle()) |
| , fShaderFlags(shaderFlags) { |
| // Bottom left origin is not supported. |
| SkASSERT(atlasView.origin() == kTopLeft_GrSurfaceOrigin); |
| } |
| |
| GrSurfaceProxy* proxy() const { return fAtlasProxy.get(); } |
| const skgpu::Swizzle& atlasSwizzle() const { return fAtlasSwizzle; } |
| |
| // Returns whether the two helpers can be batched together in a single draw. |
| bool isCompatible(const AtlasInstancedHelper& helper) { |
| // TODO: We may want to consider two helpers compatible if they only differ in the |
| // kCheckBounds flag -- we can always promote one to checking its bounds. |
| SkASSERT(fAtlasProxy != helper.fAtlasProxy || fAtlasSwizzle == helper.fAtlasSwizzle); |
| return fAtlasProxy == helper.fAtlasProxy && fShaderFlags == helper.fShaderFlags; |
| } |
| |
| // Adds bits to the shader key that uniquely identify this specific helper's shader code. |
| void getKeyBits(KeyBuilder* b) const; |
| |
| // Appends the instanced input attribs to the back of the array that we will need in order to |
| // locate our path in the atlas. |
| void appendInstanceAttribs( |
| skia_private::TArray<GrGeometryProcessor::Attribute>* instanceAttribs) const; |
| |
| struct Instance { |
| Instance(SkIPoint16 locationInAtlas, const SkIRect& pathDevIBounds, bool transposedInAtlas) |
| : fLocationInAtlas(locationInAtlas) |
| , fPathDevIBounds(pathDevIBounds) |
| , fTransposedInAtlas(transposedInAtlas) { |
| SkASSERT(fLocationInAtlas.x() >= 0); |
| SkASSERT(fLocationInAtlas.y() >= 0); |
| } |
| SkIPoint16 fLocationInAtlas; |
| SkIRect fPathDevIBounds; |
| bool fTransposedInAtlas; |
| }; |
| |
| // Writes out the given instance data, formatted for the specific attribs that we added during |
| // appendInstanceAttribs(). |
| void writeInstanceData(VertexWriter* instanceWriter, const Instance*) const; |
| |
| // Injects vertex code, fragment code, varyings, and uniforms to ultimately multiply |
| // "args.fOutputCoverage" in the fragment shader by the atlas coverage. |
| // |
| // The caller is responsible to store "atlasAdjustUniformHandle" and pass it to |
| // setUniformData(). |
| void injectShaderCode(const GrGeometryProcessor::ProgramImpl::EmitArgs&, |
| const GrShaderVar& devCoord, |
| GrGLSLUniformHandler::UniformHandle* atlasAdjustUniformHandle) const; |
| |
| // The atlas clip requires one uniform value -- "atlasAdjustUniform". The caller should have |
| // stored this handle after its call to injectShaderCode(). This method sets its value prior to |
| // drawing. |
| void setUniformData(const GrGLSLProgramDataManager&, |
| const GrGLSLUniformHandler::UniformHandle& atlasAdjustUniformHandle) const; |
| |
| private: |
| const sk_sp<GrSurfaceProxy> fAtlasProxy; |
| const skgpu::Swizzle fAtlasSwizzle; |
| const ShaderFlags fShaderFlags; |
| }; |
| |
| GR_MAKE_BITFIELD_CLASS_OPS(AtlasInstancedHelper::ShaderFlags) |
| |
| } // namespace skgpu::ganesh |
| |
| #endif // AtlasInstancedHelper_DEFINED |